said press



F. 1. REICVHM'ANN AND LPM-iss.

TELEPHONE INSTRUMENT.

APPLICATION FILED JUNE 21,1913` I L34?, 1 75. Patented July 20, 1920.

Ngl.

Illllllllllllll l .v .villllllllllllllla'lllll "HIER" UNITED sTATiazs PATENT OFFICE.

FRANK J. REICHMANN AND JOHN PRESS, 4OIE CHICAGO, ILLINOIS; SAID PRESS `.ASSIGrII'OR T0 SAID REICHMANN. Y

TELEPHONE INSTRUMENT.

Specification of Letters Patent. Patented July 20, 1920.

I Application lfiled .Tune 21, 1918. Serial No.. 241,135.

To all whom t may concern.'

v MANN and JOHN. PRESS, citizens of the United States, residing at Chicago, in the county. of Cook and State of Illinois, have invented a new and useful Telephone Instrument, of which the following is a speci fication. v

Our present invention relates to improvements in telephone instruments and more especially to a novel form of carbon receptacle particularly suited for use on an amlifier in loud-speaking telephone circuits. he invention will be fully understood from the following specification, taken in connection with the accompanying drawings, in which- Figure 1 is asectinal view through the operating mechanism of the carbon button; Fig. 2 is a section on the line 2 of Fig. 1; Fig. 3.is an enlarged section through a modi- 'ed form of the button; Fig. 4 is an enlarged face view of the spring-spider employed in our improved button; and Fig. 5 is a side elevation of a different construction of the button.v f

The construction illustrated by Figs. 1 and 2 `is substantially the same as that described and claimed in our co-pending application, Serial No. 241,134, filed 'June ,21,

1918 and will therefore be described only briefiy inthe present specification. As here shown, it comprises a head 10, of generally disk-like form, and having secured to its back a modified horseshoe magnet 11, made up of two laminations. A stud pole-piece 12 secured to both laminations at one end of the magnet has a spool-winding 13 thereon. :The other pole of the magnet is formed by bending upwardly or outwardly the ex,-

tremity of the upper lamination to bring it.

substantially into the plane of the faceof the stud 12. This bent extremity has al knife-edge pivot 15 formed thereon, which serves to vbalance an armature 16, the outer end of which extends over the stud pole 12, clearing the latter by a few thousandths of an inch, while the inner end extends to the approximate center of the'head and there has secured in an aperture a link 17, which forms a yconnection to the carbon button.` The armature 16 is held in place on'theknife-edge pivotby a pin-and-socketbearing formed by anoverhangin'gflexible arm 18. rThe upturned extremity of themagnet'.

is adjusted toward and away from the plane of the magnet by a wedge-screw 19, which iexes this upturned extremity to increase or decrease the clearance between the armature and the stud-pole-piece.

The carbon button, to the construction of which our present invention particularly relates is housed within a cup-shaped metal casing 20, the flanged open end of which is secured directly to kthe outer face of the head 10.

In Fig. 3 there is shown a modified form of cup-casing, designated 20 an having an integral neck20a, which is fastened by a setscrew in the boss of a .bridge-piece 2.01 this arrangement being useful in connection with an ordinary type of telephone transmitter.

-In Fig. 5 the cup-casing designated 20c.is formed integrally with a transmitter diaphragm20d. The `internal construction of the button, as fitted within these different forms of casings,iis as follows. 4

In the base of the cup there is mounted..

a carbon disk 21, upon which there bears lan asbestos paper disk 26. Spacing washers 27 interposed between the center kof the paper disks 23, 26 and the spider 25, hold the latter .in the dished shape illustrated. The link 17 extendsvthrou'gh central aper- 'tures in the-asbestos paper sheets 23, 26 and the 2spider-25, and by means of nuts serves to secure against the faces of the sheets 23 and 26 carbon-disk electrodes 28, 29, of approximately, the shape and size shown.

Y Within the spaceformed bythe outer shoul` Ader of the annulus .24'there is secured-.a thin carbon disk 30, .which is backed or reinforcedby a brass annulus 31, which likewise serves; as one of the electrode terminals ofil the button. `The. brass disk 31 is insulated from the cup 2O`by1a mica annulus 32, of the full diameter of the interior of the cup. An

111.fx1-,he'parts'4 in `their assembled positions Vand is'- itself secured, as for example, by

nicking'the metal ofthe cup, as shown at outer ,metalliewasher or annulus 33 holds f' a plurality of points around the periphery o r, optionally, continuously' around the pee rlphery. ,An insulating and packing gland for the metallic link 17, where the latter passes through the carbon diskBO, is formed by a Wad of flufy asbestos,designated 35. The separate interior chambers withiny the button areeach filled with "granular carbon, designated 37.

Although we have-.shown and described v in considerable detail a preferred embodiment of our invention as used in connection v with some particular forms of vibration prof ducing or reproducing means, it will be unv derstoodthat 'this is illustrative only and l for the purpose of making the invention more clear and. that the invention is not limited to the details of construction mentioned nonlto the use-of the instrument de scribed, except in so far as such .limitations are included within the terms of the accomvand spaced away fromthe panying claims, in which it is our intention to claim all novelty inherent in our inven` tionas 'broadly as is permissible inview of the prior art..

' What we regard as new and desire'to Asecure by Letters Patent is: i

l. In a carbon button for telephony, a compound diaphragm dividing the'mass of granular carbon intoseparate portlons and comprising a Adished, flexible disk-like member secured between resilient sheets.

2. In a carbon button for telephony, a compound diaphragm dividing the mass of granular carbon into separate portionsand comprising a central vflexible metallic mem- Y 

